The most significant new feature of the Apple Watch Series 6 is the ability to measure your blood’s oxygen saturation.

This is particularly relevant to the state of the world today, because people with COVID-19 may have low blood oxygen levels.

Some people with COVID-19 released from the hospital are also given a pulse oximeter so they can continue to monitor their oxygen levels as they recover at home.

Experts say this kind of data is best understood with the help of a primary care physician or specialist.

“Consumer wearable devices are not meant to diagnose conditions,” said Amanda Paluch, PhD, a physical activity epidemiologist and kinesiologist at the University of Massachusetts Amherst.

“You should seek professional consultation and have measures performed in a clinic, not rely on your data from a consumer wearable device,” she said.

Blood oxygen monitoring may be more helpful for people with an existing — and already diagnosed — chronic health problem. This is where Apple’s research projects come in.

Apple announced in a news release that it’s working with the University of California, Irvine and insurer Anthem to see if ongoing monitoring of blood oxygen levels and other signals from the body can help people manage and control their asthma.

It’s also working with two other institutions on a similar project focused on heart failure.

The third project will look at whether the Apple Watch can help detect respiratory conditions such as seasonal influenza or COVID-19 based on changes in heart rate and blood oxygen levels.

Delesha Carpenter, PhD, MSPH, an associate professor in the division of pharmaceutical outcomes and policy at the University of North Carolina at Chapel Hill, said wearable devices can help people manage chronic conditions such as asthma, high blood pressure, and diabetes.

“This is especially useful for parameters that the person may not be able to directly sense themselves,” she said. “In this way, wearables can provide useful input about whether their disease state is worsening.”

The main appeal of commercial wearables is that they’re widely available and integrate well with iOS and Android smartphones.

But the high cost of these products may keep them out of the hands of some people with chronic conditions.

“Many economically disadvantaged patients are affected by asthma and would not be able to afford an Apple Watch,” said Carpenter.

Most of the other new features of the Apple Watch Series 6 are aimed at boosting people’s overall health.

First, there’s a feature that detects how often you wash your hands. If a worldwide pandemic hasn’t helped you build a handwashing habit by now, then you might as well try letting a watch remind you.

And then there’s sleep tracking, something that many smartphone apps offer.

This can provide insight into your sleep patterns. But as with blood oxygen levels, you should talk to your doctor if you have concerns about the data you’re seeing.

There are also several exercise-related features: an always-on altimeter (so you know your elevation throughout your workout), new workout types, and VO₂ max (a measure of your aerobic fitness).

Paluch said we’ve known for years that cardiovascular fitness is important to our health, but helping people know how much physical activity they need to do — and how intensely — can be challenging.

Technologies that help people estimate their fitness outside a laboratory and in their own homes and neighborhoods is a good thing, she said.

“Estimate is a key word here,” said Paluch. “These measures provide an estimate of fitness, not your absolute true fitness level.”

Wearable devices that monitor heart rate or calculate VO₂ max may not be as accurate as the tools used by fitness scientists — and accuracy can vary widely among commercial products.

Paluch said data from wearables such as the Apple Watch are most useful for seeing how your fitness improves over time — for example, how much faster you can walk up and down a flight of stairs after sticking to a walking program for a month.

These devices can also help you become more mindful about your health behaviors, she said.

Are you sitting for extended periods? Should you be walking more throughout the day? Did you wash your hands recently?

Not everyone, though, will find it motivating to have a constant stream of data about their body. For some, this information can be downright anxiety-provoking.

In addition, Paluch said people’s use of wearable fitness devices tends to decline after 3 to 6 months. So building healthier habits is often more important than which gadget you have strapped to your wrist.

“An individual’s health will only be impacted if they are able to make long-term change,” said Paluch. “The device will not make the change, but can be a tool to get there.”